1. Field
Exemplary embodiments of the present invention relate to fabrication of a semiconductor device, and more particularly to an image sensor and method for fabricating the same.
2. Description of the Related Art
An image sensor is a device for converting an optical image into an electrical signal. Image sensors are generally categorized as charge coupled device (CCD) types and CMOS image sensor (CIS) types. The image sensor has a plurality of pixels disposed in the form of a 2 dimensional matrix. Each of the plurality of pixels outputs a pixel signal corresponding to incident light. The pixel accumulates a photocharge corresponding to the incident light through a photoelectric conversion element represented by a photodiode and outputs the pixel signal based on the accumulated photocharge.
A dark current is induced due to a charge generated at the surface of substrate where the photoelectric conversion element is disposed in the image sensor. The dark current acts as noise to the pixel signal, and thus deteriorates the properties of the image sensor.